Thank you
Citation500 
, that's exactly what I meant. Avoiding action given by ATC
then RA. Seen it happen.
As to regularity, in high density airspace RA can be triggered by high rates of climb/descent of closing traffic before they level off. As TCAS is timed based, the system ascertains a "closest point of approach" of the traffic and provides a resolution if required.........not knowing the other aircraft will be levelling off.